Sign



April 28, 1931. J. HORNIBROOK SIGN Filed Oct. 29; 1929 t In vemfor k/Zi/iz fforizzfimoii,

A itorney Patented Apr. 28, 1931 JOHN I-IORNIBROOK, OF SALT LAKE CITY, UTAH SIGN Application filed October '29, 1929.

' This invention relates broadly to signs, and has more particular reference to display signs for attracting the attention of passersby.

A primary object of this invention is therefore to provide a sign having novel features of construction whereby when the sign is viewed from any angle by observers, the sign will have the appearance of various colors dependent uponthe angle at which the sign is viewed.

The invention consists in the provision of a plate preferably of glass one face of which has been rendered opaque except for a certain area, and secured to said one face of the glass and disposed over that area of the glass which has not been rendered opaque is a grating, which grating may be made of celluloid or some other substance pasted or otherwise affixed to the glass in the form of letters or figures, the grating being of a peculiar construction so that light shining from either behind or in front of the glass will cause various colors to be observed by one passing the sign.

A still further object of the invention is to provide a sign of the above mentioned character, which will readily attract the attention of passersby, is simple in construction, can be disclosed at any convenient place, whereby to attract the attention of observers, and wherein the sign may be manufactured at a relatively low cost, consisting of but comparatively few parts, and

which is otherwise well adapted for the purpose designed.

Other objects and advantages of the invention will become apparent from a study of the following description, taken in connection with the accompanying drawings wherein:

Figure l is a top edge view of a sign constructed in accordance with the present invention,

Figure 2 is a front plan view of the sign,

With reference more in detail to the drawings, it will be seen that my improved sign consists of a backing plate 5, which backing plate 5 may be of elongated rectangular configuration and is preferably in 'ductions of a series of ruled lines; or dif- Serial No. 403,262.

the nature of a pane of glass or similar transparent material.

On the front face thereof, the backing plate or glass pane 5 is painted or otherwise treated to be rendered opaque as at 6. In this connection, it is to be noted that only a certain area of the front face of the glass pane is rendered opaque, the remaining area of the pane still remaining transparent.

Secured to the front face of the plate either by gluing or otherwise, is a diffracting element or body 7. This difiracting element 7 is in the nature of a grating and may consist of a strip of celluloid or like material so out as to form a figure or a letter such as the letter D and the figure l as shown in the drawing, and only that area of the front face of the pane 5 to which this diffracting medium or grating 7 is secured remains transparent, the remaining portion of the front face of the glass being rendered opaque as before mentioned.

The celluloid strip or other similar material forming a difi'racting grating 7 has 75 on the front face thereof, a plurality of closely spaced parallel lines 8, which lines 8 may be ruled, drawn or otherwise formed on said celluloid material. In this connection it may be well to mention that the diffracting grating 7 may be originals, ruled by means of a dividing engine; replicas of the originals, madeby photographic means or by a. casting process; photographic refraction gratings made by any other process. 7 The 'manner of forming such grates of replicas are well known in the art and a more detailed description thereof is therefore deemed unnecessary.

In actual practice when the sign is so formed as above described is placed in a position of display, light shining either from behind or in front of the glass plate 5 will pass through the grating and is spread out into spectra of the first, second, third orders, etc.

In the event that the light shines from the front, the grating must be fixed or ruled on a reflecting surface, as is apparent.

In forming the grating, there are about ten thousand lines per square inch, which wth the light shining through the grating a before mentioned will cause a formation 5 of various colors. Thus as indicated in Figure 1, it will be seen that the light passing through the grating will be of different colors such as ll e, red, blue in a ternating succession.

The colored beams are so diffracted as to appear at an angle, while a direct line through the center of the grating will be white as marked so that, as obvious, the spectra is in its proper order until it ends with red.

Thus it will be appreciated, that the rays of light passing through the grating and so diffracted form spectra according to the ordinary laws of diffraction. Thus, the

moving eye of the observer will meet in succession the colors of the spectra so that the .sign appears to change color with each dif iferent observation point. I

5 For example, the eye is at C, the diffracting grating 7 will appear red, when at B,

blue; and when at A white, etc.

In actual practice, it is of course to be understood that the sign is set up, suspended or otherwise disposed as to be in a substantially vertical position, so that the light rays may shine therethrough. It is to be understood that I do not wish to limit the use of a diffraction grating of this character on a backing plate such as hereinbefore described, such being only used when the grating is utilized as a sign, for advertising purposes, and the like, since in actual practice the grating per se could be affixed to other objects such as a cigarette lighter, a compact, a base or many other novelties,

with the result that in viewing the object to which the grating is aflixed at different angles, a different color would be observed.

t is believed that from the foregoing description taken in connection with the accompanying drawings, a clear understand- 5 ing of the operation, construction, utility i and advantages of a sign of. this character will be had by those skilled inthis art. A more detailed description thereof is therefore deemed unnecessary.

Even though I have herein shown and described the preferred embodiment of my invention, it is to be understood that the same is susceptible to certain changes and modifications coming within the field of invention as herein described, and scope of the appended claims.

Having thus described my invention, what I claim as new is:

1. In a sign of the character described, a backing plate having a certain area thereof transparent and the remaining area of the plate being opaque, a diifracting grating secured to. the backing plate disposed over the entire transparent area of said backing plate, whereby light rays passing through the grating are spread out into the spectra of the first, second and third orders, etc., and said diffracting grating comprising a sheet of translucent material having closely spaced parallel lines formed thereon and aflixed adhesively to the backing plate to form an indicating character.

2. In a sign of the class described, a backing plate formed of glass or like transparent material, said plate having the front face thereof made opaque over a certain area, a sign composed of indicia characters secured to said backing plate and disposed over the last mentioned area of the plate, each of said indicia characters consisting of a strip of celluloid having a plurality of closely spaced lines formed thereon so that light rays passing through said late and said strip of celluloid will be di racted to form spectra whereby the moving eye of an observer will meet in succession the colors of the spectra so that said sign will appear to change colors when viewed from a different point of observation.

In testimony whereof I affix my si nature.

JOHN HORNIBR OK. 

